RESUMO:Croton cajucara Beth (Euphorbiaceae) uma espécie medicinal nativa da região Amazônica do Brasil, onde é vulgarmente conhecida como 'sacaca', representa um recurso terapêutico efi caz no tratamento e cura de várias doenças. O metabólito majoritário transdesidrocrotonina (DCTN), isolado das cascas do caule desta planta, encontra-se correlacionado com grande parte das propriedades medicinais da sacaca. Este artigo de revisão, descreve os resultados fi toquímicos e farmacológicos que foram realizados com o diterpeno do tipo clerodano DCTN, bem como seus derivados semi-sintéticos. Adicionalmente, apresenta perspectivas para a biodisponibilização deste protótipo de fármaco em nanosistemas. Unitermos:Croton cajucara, trans-desidrocrotonina, DCTN, fi toquímica, atividade biológica, nanobiotecnologia.ABSTRACT: "A review of the biologic activities of trans-dehydrocrotonin, a natural product obtained from Croton cajucara". Croton cajucara Beth (Euphorbiaceae) is a plant found in the Amazonian Region of North Brazil, where it is popularly known as sacaca. The major secondary metabolite, trans-dehydrocrotonin (DCTN) a clerodane-type diterpene, isolated from the stem bark is a chief bioactive compound of Croton cajucara. This review describes results of extensive pharmacological studies of DCTN, as well as its semi-synthetic derivatives, and also presents insights into the use of DCTN as a therapeutic agent and some potential advantages of its incorporation in drug delivery systems.

In the present study, poly (D,L-lactic-co-glycolic)-acid microspheres containing trans-Dehydrocrotonin (DCTN) were prepared by the double emulsion method. The hypoglycemic activity of DCTN-loaded microspheres was monitored in normal glycemic mice after administration of a daily dose of DCTN (50 mg kg(-1) body weight) for 7 days. Spherical microspheres with two populations of particles with 3.20 +/- 0.10 and 7.60 +/- 0.70 microm mean diameter size microm were observed. The encapsulation efficiency of DCTN was 85.5 +/- 3.9%. The in vitro kinetic profile of DCTN from PLGA-microspheres was initially fast (burst effect of 19.4% at 2 h). Such a burst step was maintained until achieving 35.7+/-2.0% at 7h, followed by a gradual release of DCTN attaining a maximum drug release at 55.7 +/- 2.6% within 30 h. DCTN was able to reduce glucose levels (14.3%) of normal glycemic animals and this effect was improved by its encapsulation into microspheres (26.8%). The optimum glucose levels in the blood of animals treated with DCTN suspension and DCTN-loaded microspheres were 119.21 +/- 19.75 mg dL(-1) at day 5 and 103.08 +/- 18.88 mg dL(-1) at day 7, respectively. DCTN-loaded microspheres are thus offered as a potential delivery system for the treatment of metabolic diseases characterized by hyperglycemia.

SYNTHESIS, ANTILESHMANIA AND CYTOTOXIC ACTIVITY OF HYDRAZONES FROM NATURAL ALDEHYDES. Leishmaniasis is endemic anthropozoonosis considered to be a severe public health problem. The treatment with pentavalent antimonials presents high toxicity motivating the search for effective and less toxic drugs. Hydrazones and N-acylhydrazones are functional groups that are prominent in Medicinal Chemistry, including as antiprotozoals. In this context, five hydrazones derived from the natural aldehydes were synthesized and the molecular structures were suitably determined to employ uni and bidimensional 1 H and 13 C NMR techniques. The antileishmanial activity of all hydrazones was determined against promastigote forms of Leishmania amazonensis, and the compounds HDZ-3, HDZ-4, and HDZ-5 showed the best results, with IC 50 of 9.00, 38.10 and 26.30 μM, respectively. In the cytotoxic evaluation against RAW macrophages, HDZ-4 presented the least cytotoxic (CC 50 = 222.24 μM) and the higher selectivity. Lipinski's descriptors of the hydrazones were calculated, and the compounds HDZ-3 and HDZ-5 were more promising. These hydrazones are hybrids of natural aldehydes with drugs, the first is the result of the junction of the cinnamaldehyde with isoniazid, and the second of the vanillin with hydralazine. The results highlighted the Markush isonicotinoylhydrazone and phthalazinylhydrazone groups, molecular structures that are present in HDZ-3 and HDZ-5 and are therefore considered innovators in the development of antileishmanial drugs.

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